Steering wheel

ABSTRACT

A steering wheel comprises a rim skeleton and a rim casing. At least one vibration-damping element is provided which is arranged between the rim skeleton and the rim casing.

TECHNICAL FIELD

[0001] The invention relates to a steering wheel.

BACKGROUND OF THE INVENTION

[0002] To increase the comfort, various attempts have been made recentlyto keep vibrations away from the steering wheel of a vehicle, whichoccur whilst the vehicle is in operation. It is known, for example, touse inertial masses to compensate vibrations, by which the resonancefrequency of the steering wheel is shifted into a non-critical range.These inertial masses can either be additional masses or suitablyarranged components of, for example, gas bag restraint systems, inparticular the gas generator. If additional masses are used, this leadsto additional costs and to an increased weight. If components of the gasbag restraint system are used, various problems arise, such as the gastightness of the gas generators or the transmission of reaction forceson activation of the gas bag.

BRIEF SUMMARY OF THE INVENTION

[0003] The object of the invention consists in achieving a neutralizingof vibrations of the steering wheel with a small expenditure.

[0004] This is achieved in a steering wheel which comprises a rimskeleton and a rim casing, at least one vibration-damping element beingprovided which is arranged between the rim skeleton and the rim casing.The invention is based on the fundamental idea of neutralizing in termsof vibration technology only that part of the steering wheel for whichthis is absolutely necessary. This is the rim casing which comes intocontact with the hands of the driver of the vehicle concerned. If therim casing is neutralized in terms of vibration technology, vibrationsof the remaining parts of the steering wheel, for example the steeringwheel hub or the steering wheel spokes, are scarcely noticed. A furtheradvantage of the construction according to the invention consists inthat through the neutralizing merely of the rim casing, only a smallervibrating mass has to be neutralized.

[0005] Advantageous developments of the invention will be apparent fromthe sub-claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 shows a steering wheel in a diagrammatic view;

[0007]FIG. 2 shows in a sectional view a steering wheel according to afirst embodiment of the invention; and

[0008]FIG. 3 shows in a sectional view a steering wheel according to asecond embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In FIG. 1 a steering wheel is illustrated diagrammatically. Itcontains a steering wheel hub 10, several spokes 12 and a rim skeleton14. On the rim skeleton 14 a rim casing 16 is arranged, which is graspedby the driver of a vehicle equipped with the steering wheel.

[0010] In FIG. 2 a cross-section is shown through the rim skeleton andthe rim casing of a steering wheel according to a first embodiment. Therim skeleton 14 is constructed here with a U-shaped cross-section whichis completely surrounded by a vibration-damping element 20, 22. Thevibration-damping element consists of a vibration-damping material,preferably of polyurethane foam, and is constructed in two parts, namelywith an upper part 20 and a lower part 22. The upper part 20 and thelower part 22 together produce a circular cross-section.

[0011] On the vibration-damping element 20, 22 the rim casing 16 isarranged, which consists of a shell having an annular cross-section andis foamed onto the vibration-damping element. Owing to the elasticcharacteristics of the vibration-damping element 20, 22, the rim casing16 is mounted on the rim skeleton 14 in a vibration-free manner or atleast in a damped manner with respect to vibrations.

[0012] In FIG. 3 a section is shown through a steering wheel accordingto a second embodiment. In contrast to the first embodiment, hereseveral rings 20 are used as vibration-damping element, which incontrast to the continuous insert known from the first embodiment arearranged spaced apart from each other, and which locally support the rimcasing. Between the vibration-damping rings 20 there is a free spacebetween the rim skeleton 14 and the rim casing 16. In the secondembodiment the rim casing 16 consists of an upper shell and a lowershell which are placed onto the vibration-damping rings and areconnected with each other to form the rim casing.

1. A steering wheel comprising a rim skeleton and a rim casing, at leastone vibration-damping element being provided which is arranged betweensaid rim skeleton and said rim casing.
 2. The steering wheel accordingto claim 1, wherein as said vibration-damping element, rings of one ofvibration-damping material and composite material are used, said ringsbeing arranged spaced apart from each other on said rim skeleton andsupporting said rim casing.
 3. The steering wheel according to claim 1,wherein as said vibration-damping element a continuous insert is used,which supports said rim casing across its entire length.
 4. The steeringwheel according to claim 3, wherein said rim casing is foamed onto saidvibration-damping element.
 5. The steering wheel according to claim 1,wherein said rim casing consists of an upper shell and a lower shell. 6.The steering wheel according to claim 1, wherein said vibration-dampingelement is foamed onto said rim skeleton.
 7. The steering wheelaccording to claim 1, wherein said vibration-damping element consists ofpolyurethane foam.